package com.wnlife.simple;

/**
 * @author Wnlife
 * @create 2020-06-13 21:29
 * <p>
 * 罗马数字转整数
 */
public class RomantoInteger {

    public int romanToInt(String s) {
        int sum=0;
        int preNum=getValue(s.charAt(0));
        for (int i = 1; i < s.length(); i++) {
            int num = getValue(s.charAt(i));
            if(preNum<num){
                sum-=preNum;
            }else {
                sum+=preNum;
            }
            preNum=num;
        }
        sum+=preNum;
        return sum;
    }

    public int getValue(char ch){
        switch (ch){
            case 'I':return 1;
            case 'V':return 5;
            case 'X':return 10;
            case 'L':return 50;
            case 'C':return 100;
            case 'D':return 500;
            case 'M':return 1000;
            default:return 0;
        }
    }

}
